1. Field of the Invention
The technical scope of the invention is that of devices to initiate an attack module which has at least one predetermined direction of action.
2. Description of the Related Art
By attack module having a predetermined direction of action, we mean a projectile or sub-projectile which acts preferentially in a given direction in space.
This is the case for projectiles or sub-projectiles incorporating a shaped charge (hollow charge or explosively-formed charge). In this case, the direction of action is that in which the slug or jet of the shaped charge is projected. By way of an example, patent FR2793314 (or U.S. Pat. No. 6,250,229) discloses a known sub-projectile with an explosively-formed charge.
It is also the case for projectiles or sub-projectiles which are splinter-forming and are designed so as to project splinters in a given mean direction. It is known, for example, to replace the charge liner of an explosively-formed charge by a case enclosing preformed splinters.
When this charge is ignited it projects a spray of splinters in a given direction which is that of the charge axis. The splinters disperse slightly around the projection axis resulting in an impact surface on a target which is of a given area (depending on the distance between charge and target). Patent EP1045222 (no known U.S. patent equivalent) discloses such a charge which projects splinters in a given direction.
Projectiles or sub-projectiles which thus have a predetermined direction of action are particularly advantageous in that they enable the danger zone to be controlled. Collateral damage can be minimized, with only the main target in principle being destroyed.
These attack modules thereby enable the effects to be restricted to a well-defined sector which was not the case for classical projectiles or sub-projectiles, for example explosive artillery shells which generate splinters in all directions in the space surrounding the shell axis.
One of the problems posed by attack modules having a predetermined direction of action is, however, that they have to be oriented in the direction of the required target.
Thus, projectiles are known which are brought into contact or into the vicinity of the target, either by direct fire (shaped charge shells fired in direct fire with no guidance) or by indirect fire.
In the case of indirect fire, it is however necessary for guidance and steering means to be provided which enable the projectile to be directed onto the target, for example orientable fins controlled by a homing device. Reference may be made to patents EP905473 (or U.S. Pat. No. 6,234,082) or FR2847033 (or U.S. Pat. No. 6,886,770 which disclose such guided projectiles.
Sub-projectiles are also known which do not have steering means but which are known to scan a zone of ground using a target detector (for example and infra-red sensor). In this case, firing is initiated when the sub-projectile detects a target presenting the required outline characteristics. Patents GB2090950 and U.S. Pat. No. 4,858,532 disclose such known sub-projectiles.
These sub-projectiles with no steering means nevertheless still suffer from certain drawbacks.
They are firstly only able to attack targets which have a well-defined and easily recognizable signature. They are therefore not able to be used against targets that are more difficult to detect.
Furthermore, with these sub-projectiles there still remains the risk of inadvertent ignition by false targets (decoys or else targets which have already been hit by another sub-projectile) or by friendly targets.